Therapeutic potential of endogenous hydrogen sulfide inhibition in breast cancer

Hydrogen sulfide (H(2)S), the third gas signal molecule, is associated with the modulation of various physiological and pathological processes. Recent studies have reevealed that endogenous H(2)S may promote proliferation, induce angiogenesis and inhibit apoptosis, thereby stimulating oncogenesis. Conversely, decreased endogenous H(2)S release suppresses growth of various tumors including breast cancer. This observation suggests an alternative tumor therapy strategy by inhibiting H(2)S-producing enzymes to reduce the release of endogenous H(2)S. Breast cancer is the most common type of cancer in women. Due to the lack of approved targeted therapy, its recurrence and metastasis still affect its clinical treatment. In recent years, significant progress has been made in the control of breast cancer by using inhibitors on H(2)S-producing enzymes. This review summarized the roles of endogenous H(2)S-producing enzymes in breast cancer and the effects of the enzyme inhibitors on anticancer and anti-metastasis, with the aim of providing new insights for the treatment of breast cancer.